Antenna Definitions and Terms
"A",
"B",
"C",
"D",
"E",
"F",
"G"/"H",
"I" to "L",
"M" to "O",
"P"/"Q",
"R",
"S",
"T",
"U" to "Z"
Magnetic {H} Field: The field produced when current flows through a conductor or antenna.
Main Lobe: The lobe containing the maximum power in an antenna radiation pattern.
Antenna Main Lobe
Major Lobe. The lobe in which the greatest amount of radiation occurs. See Main Lobe.
Marconi antenna: A quarter-wave antenna oriented perpendicular to the earth and operated with
one end grounded.
Mast: A vertical antenna tower. An antenna support.
Maximum Usable Frequency: [MUF] The highest frequency for a given
elevation angle that will reflect from an ionospheric layer.
Megahertz: One million cycles per second. Also called MHz.
Minor Lobe Ratio. The ratio of the major lobe amplitude to the highest minor lobe, expressed in dB.
MLPV: Mobile Low Profile Vertical Antenna
Mobile Antenna: An antenna used in mobile applications.
Modulate: To change the output of a transmitter in amplitude
phase, or frequency in accordance with the information to be transmitted.
Monopole antenna: An antenna with a single radiating element; a
whip antenna. [Whip Antenna graphic to the right]. Also see Conical Monopole, but the graphic is shown below.
Multi-Arm Spiral Antenna: [MASA] See Spiral Antenna.
Multiband Antenna. An antenna that may be used at more than one frequency band.
Multicoupler. A device used to interface one antenna to several receivers with a gain of one or larger.
Multielement Array. An array that consists of one or more arrays and is classified as to
directivity.
Multi-element Dipole Antenna: An antenna consisting of an arrangement of multiple dipole antennas.
Multielement Parasitic Array. An array that contains two or more parasitic elements and a
driven element.
Multipath: The multiple paths a radio wave may follow between transmitter and receiver. May also be called Multipath delay. Signals reaching a receiving antenna by two or more separate paths.
Multipath Distortion: The distortion caused by a radio receiving the same signal from multiple paths, at different times [delayed].
Multi-turn loop (MTL) Antenna A loop antenna with more than one loop.
Natural Frequency: Of an antenna, the lowest frequency at which the antenna resonates without the addition of any inductance or capacitance.
Near Field: A region generally in close proximity to an antenna or other radiating structure in which the
electric and magnetic fields do not exhibit a plane wave relationship and the field strength
does not decrease proportionally with the distance from the source but varies considerably.
Necessary Bandwidth. The width of a frequency band which is just sufficient to ensure the transmission of information at the rate and with a quality required.
Node: The fixed minimum points of voltage or current on a standing wave or antenna.
Noise: Random pulses of electromagnetic energy generated by
lightning or electrical equipment. Any unwanted disturbance or spurious signals which modifies the transmission of a signal.
Non-directional Antenna: See Omnidirectional antenna.
Non-resonant Antenna: See aperiodic antenna.
Notch Antenna: An antenna that has a notch or slot in its radiating surface..
Null: A zone in which the effective radiated power is at a minimum relative to the maximum effective radiated power of the main beam in an antenna radiation pattern
Nutating: Moving an antenna feed point in a conical pattern so that the polarization of the beam does not change.
Offset angle: The angle at which a long wire antenna must be aimed on either side of the direction to the base station.
Omnidirectional Antenna: An antenna whose radiation pattern
shows equal radiation in all horizontal directions. An antenna that has a radiation pattern that is non-directional in azimuth.
Orange Peel Antenna: An antenna shaped as the peel of an orange, with a long and narrow reflector. Orange Peel antennas are used in radar applications. A style of antenna used with search radar applications. |  Orange Peel Antenna |
Orthogonal Antenna. An antenna with elements that are perpendicular to each other.
Oscillation: A periodic, repetitive motion or set of values (voltage, current, velocity).
Outdoor Antenna. An antenna located outside a structure, normally elevated in height.
Out of phase: Two alternating quantities not passing through corresponding
values at the same time (e.g., if the current in a circuit reaches its maximum value before or after the applied voltage does,
the current is out of phase with the voltage).
